Support is requested to continue human health-oriented research on risks from exposure to chemicals commonly found in Superfund sites and on new clean-up technologies to eliminate the potential for exposure to chemicals from thos3e sites. The pollutants under investigation include relatively water soluble chemicals that contaminate groundwater such as trichloroethylene and environmentally persistent lipid soluble chemicals such as PCBs and PAHs. A highly integrated, multi-disciplinary research program is proposed consisting of nine research projects and four supporting core units. The research team of 24 investigators include faculty at nine research projects and four supporting core units. The research team of 24 investigators include faculty at Michigan State University (12), The University of Michigan (8), Stanford (2), Rutgers (1) ant the Oak Ridge National Laboratory (1). The major thrusts of the research are in four areas: 1) understanding the mechanisms of factors controlling the environmental persistence and bioavailability of contaminants to microbes involved in biodegradation, 3) determination of the effectiveness of purposefully altered (engineered) subsurface environments on the rates of biodegradation and 4) evaluation of chemical products produced from environments on the rates of biodegradation and 4) evaluation of chemical products produced from bioremediation for toxicity potential, 3) determination of the effectiveness of purposefully altered (engineered) subsurface environments on the rates of biodegradation and 4) evaluation of chemical products produced from bioremediation on the rate of biodegradation and 4) evaluation of chemical products produced from bioremediation for toxicity potential. The research projects classified as biomedical include studies examining the effects of PCBs to cause immunotoxicity, reproductive and developmental toxicity, and developmental neurotoxicity, Site remediation research includes reproductive bioremediation of groundwater contaminants, the synthesis and development of novel macrochemical to participate in retention of chemicals to participate in retention of chemicals in groundwater plumes containing halogenated solvents and metals, and an examination of factors that control the rate of groundwater and soil bioremediation. A core laboratory will coordinate the testing of the intermediate and end products generated from biodegradation of PCBs and other contaminants commonly found in mixed waste. This testing will permit modification of experimental remediation processes to maximize the detoxification of toxic mixtures found in the environment. A postdoctoral training program will involve cross training experiences to improve the ability of recent Ph.D. graduates to perform in multi-disciplinary research teams. An Outreach Core will partner with the community assistance component of an EPA Hazardous Substance Research Center at the University of Michigan to produce information materials for use in working with communities impacted by the threat of exposure to hazardous chemicals.